A woman died on a rollercoaster at the Six Flags Over Texas amusement park in Arlington, Texas, apparently after falling out of her seat, a witness told local media.

"She goes up like this, then when it drops to come down, that's when it [the woman's restraint] released and she just tumbled," Carmen Brown told ABC News affiliate WFAA, adding that she had been next in line to ride the coaster at the time.

The accident happened just after 6:30 p.m. local time, The Associated Press reported, citing police records.

The death appeared to be an accident, Arlington police told WFAA, and the probe of the incident was not a criminal investigation.

Official details were not immediately available on how the woman died, though the park released a written statement confirming the death.

"We are deeply saddened to share that earlier this evening an adult woman died in the park while on the Texas Giant," wrote Sharon Parker, communications manager for Six Flags Over Texas. "Park medical staff and local paramedics responded immediately. Since the safety of our guests and employees is our number one priority, the ride has been closed pending further investigation. Our thoughts and prayers are with the family and friends during this difficult time."

The Texas Giant rollercoaster debuted as an all-wooden ride in 1990, and reopened in 2011 redesigned with a steel track, WFAA reported.

It rises 14 stories high and boasts "the steepest drop of any wooden coaster at 79 degrees," Six Flags Over Texas said on its website. "The new ride also has a record-breaking bank of 95 degrees, steeper than any other wooden coaster on the planet."